Already pre-assigned block element for a new post

I currently manually set a link under every blog post that invites you to comment.
This is a mailto link that generates the blog post in the subject and text in the body.
To do this, I’ll copy the block from the last blog post and paste it modified under the new one.
Can I somehow store this as a template so that the subject of the email (can also be the publication date) is automatically adopted? And can I also use a button for this? My button element doesn’t allow mailto link by default…
Thanks.

Please see Blocks | Kirby CMS

If you want to make it a button, you need a custom block type

Thank you Texnixe,
If I don’t have any fields to fill or details to edit, but just want to reuse this block saying “Comment via eMail” in the same way, what do I have to do?
Do I still need a blueprint?
The dynamic part would just be the link:
mailto:test@test.com?subject=Blogposting%20xy&body=Text

Thank you for every tip.